This invention is particularly adapted for use in the manufacture of small, fragile semiconductor devices or integrated circuits of the so-called beam lead type. Examples of these beam lead devices are disclosed in M. P. Lepselter U.S. Pat. Nos. 3,287,612 and 3,335,338. The invention is adapted to be used in conjunction with picking up, holding and maintaining orientation of small articles, but will be particularly described with respect to beam lead transistor devices which comprise a semiconductor body on which leads bonded as an integral part of the device extend from the body like cantilever beams to form both electrical and mechanical connections to a header or circuit pattern formed on a substrate. These beam leads are essentially of gold which is electroplated onto a semiconductor body which will be hereinafter designated a wafer.
A typical beam lead device is very minute, the leads being only 10 microns thick, 3 mils wide and 9 mils long while a square wafer body is only 2 mils thick and 18 mils wide.
In batch manufacture of these fragile devices, a plurality of arrays of beam leads are electroplated to extend from a number of active or doped areas formed in a slice or sheet of semiconductor material such as silicon. The slice is secured to a mounting plate with wax so that the beam leads are embedded in the wax. The nonwaxed surface of the slice is masked with a photosensitive resist to expose the areas between individual transistors and these exposed areas are etched to separate and form a plurality of individual beam lead transistor devices.
Heretofore, the resist and wax were removed by use of suitable solvents. This treatment resulted in a loss of the orientation of the transistor devices on the mounting plate, or if the devices were left in an oriented array on the plate, there was no way of moving the plate from the fabrication location to another manufacturing location without loss of the device orientation. A number of mechanical apparatus of the vibratory or shaker type were developed and tried in an attempt to regain orientation of the devices to enable subsequent manufacturing operations to be performed on the devices. However, these apparatus proved less than satisfactory because of damage to the beam lead device or slow operating capabilities in providing a supply of devices for the subsequent manufacturing operations. These subsequent operations may include testing of the devices or the assembly and bonding of the devices into integrated circuit modules. For economic mass production, it would be advantageous if the devices could be transferred from the batch fabrication location in oriented array to permit facile handling, feeding or loading of the devices into automatic testing or bonding machines.
The need for maintaining device orientation without individual handling of the devices may be further appreciated by noting that it is very difficult to transfer beam lead devices of this minute size without damaging or bending the leads, or without chipping or scratching the wafers.